A0592
Title: Estimation and inference on the partial volume under the ROC surface
Authors: Katherine Young - University of Kansas Medical Center (United States) [presenting]
Leonidas Bantis - University of Kansas Medical Center (United States)
Abstract: Summary measures of biomarker accuracy that employ the receiver operating characteristic (ROC) surface have been proposed for biomarkers that classify patients into one of three groups: healthy, early-stage, or advanced-stage disease. The well-known volume under the ROC surface (VUS) summarizes the overall discriminatory ability of a biomarker in such configurations. However, the VUS includes thresholds associated with clinically irrelevant true classification rates (TCRs). For example, due to the lethal nature of pancreatic cancer, thresholds associated with a low TCR for identifying patients with pancreatic cancer may be undesirable and not appropriate for use in a clinical setting. We study the properties of a more focused criterion, the partial volume under the ROC surface (pVUS), that summarizes the diagnostic accuracy of a marker in the three-class setting for regions restricted to only those of clinical interest. We propose methods for estimation and inference of the pVUS under parametric and non-parametric frameworks and apply these methods to the evaluation of potential biomarkers for the diagnosis of pancreatic cancer.
